What is the difference between IS NULL & IS NOT NULL?
IS NULL
checks to see if the cell is empty but IS NOT NULL
checks to see if the cell is not empty.
Example :
SELECT id FROM users WHERE 'user_type' IS NOT NULL;
SELECT id FROM users WHERE 'user_type' NOT IS NULL;
Note: This is very essential MySQL query interview questions.
BY Best Interview Question ON 14 Dec 2019